It is known that the human heart includes a right ventricle, which is used for circulation of venous blood (blue blood) and a left ventricle which serves for the circulation of arterial blood (red blood).
The blood from the venous system arrives into the right ventricle and leaves therefrom through the pulmonary artery which transports venous blood to the lungs.
Coming out of the lungs, oxygenated blood returns to the heart through the pulmonary veins, arrives into the left ventricle and leaves therefrom through the aorta towards the arterial system.
In the vast majority of cases, heart defects originate in the left ventricle.
It is known to use a pump to assist the heart in circulating blood in replacement of the left ventricle. This pump is typically part of a bypass arrangement implanted in parallel with the left ventricle.
Such a bypass system includes, in addition to the pump, an upstream end connected to a left ventricular tip and the other end connected to the inlet opening of the pump, and a downstream conduit having an extremity connected to a discharge opening of the pump and the other end connected to the aorta at the outlet of the left ventricle.
There are various known types of pumps that perform as left ventricular cardiac assist devices: in particular, centrifugal pumps with an inlet opening and a discharge opening that are arranged transversely to each other, and helical screw pumps with an inlet opening and a discharge opening aligned in an axial direction.
U.S. patent application U.S. 2012/0134832 describes a cardiac assist pump comprising an impeller rotor and a shaft provided with electric motor magnets and a casing having an intake opening and a discharge opening aligned in an axial direction. This casing includes a part forming a stator disposed around the rotor shaft, provided with stator windings of the electric motor, the magnets cooperating with the rotor shaft to rotate the latter.
Some pumps are designed to be implanted in a heart or in an artery. Such pumps are described for example in the U.S. patent application U.S. 2012/0088954 or UK Patent Application GB 2451161.